Hitherto, there have been proposed various kinds of sensor devices that detect characteristics of an illumination object by applying light from a light-emitting element to the illumination object and by causing a light-receiving element to receive specularly reflected light and diffusely reflected light from the illumination object. Such sensor devices are used in a wide range of fields, and are used in various applications, such as in photo-interrupters, photocouplers, remote control units, IrDA (Infrared Data Association) communication devices, optical fiber communication devices, and original size sensors.
For example, as described in Japanese Unexamined Patent Application Publication No. 2007-201360, a sensor device including a light-emitting element and a light-receiving element that are disposed on the same substrate and a light-intercepting wall that separates a light-receiving region and a light-emitting region is used.
However, in such a sensor device, light from a gap occurring between the substrate and the light-intercepting wall makes it difficult to increase the sensing performance of the sensor device.